Seal for rotating shafts



Feb. 10, 1942.

w. c. KEERAN 2,272,526

SEAL FOR ROTATING SHAFTS fiz nfor' fi/zawe 621 662 (17a a &M;,, ,im'm MJ W Patented Feb. 10, 1942 SEAL FOR ROTATING SHAFTS' WilliamyC. Keeran,Evanston, 111., assignor to -Bell & Gossett Company, Chicago, 111., acorporation of Illinois Application February 28, 1941 SerialNo. 381,025

2 Claims.

My invention relates to seals for rotating shafts and is moreparticularly concerned with preventing leakage of fluid along the shaftand" beyond a wall through which the shaft extends.

One object of my invention is to provide a seal in which leakage alongthe shaft and across the face of the wall transverse of the shaft isinhibited, respectively, by a resilient packing element and anannulargzsealing ring which are mounted on and individually driven bythe shaft.

A further object is to provide a seal of the foregoing character inwhich the sealing ring is resiliently maintained in sealing contact withthe wall, and the packing element is resiliently maintained in contactwith the ring.

A further object is to devise a seal as indicated wherein th elementwhich seals the surface of the shaft is made of rubber, synthetic ornatural, and in which provision is made for swelling of the element whenexposed to hot fluids without danger of binding any part of the seal.

These and further objects of my invention will be set forth in thefollowing specification, reference being had to the accompanyingdrawing, and the novel means by which said objects are effectuated willbe definitely pointed out in the claims.

In the drawing:,

Fig. 1 is a sectional elevation of my, improved seal, showing the samein operative relation to a rotating shaft and a wall through which theshaft extends.

Fig. 2 is a section along the line 2-2 in Fig. 1, showing the drivingconnection between the shaft and one of the sealing elements of thestructure.

Fig. 3 is a dispersed assembly showing in perspective the principalelements of my improved seal.

Referring to the drawing, the numeral designates my improved sealwhichis mounted on a shaft H to prevent leakage of fluid along the theopening in the wall l2 through which the shaft I I extends and providingan annular flange on the right end of this bushing against which thesealing ring l4 rides. The ring It may be made of any high grade bearingmetal that is capable of being machined to provide an anti-- surface ofthe shaft and also in leakage-inhibiting relation to a wall member l2through which 1 the shaft extends. It willbe understood that the shaftmay be journalled in the wall l2, as shown, or it may extend through thewall in clearance relation thereto without affecting the scope of thepresent invention.

provide a smooth bearing surface against which the ring l4 rides with asealing contact. It is contemplated that instead of employing the bossfriction and leakeproof surface when pressed against the boss l3, but,preferably, the ring 14 is made of carbon, since this material isrelatively inexpensive, wears smoothly in use, and will always preventleakage when held against the surface of the boss I3 with sufficientpressure.

The ring 14 may be mounted in an annular groove l5 providedin aholder itthat is coaxially provided with a non-circular opening 11, in this caseshown as being hexagonal in shape, which fits a similarly shaped portionl8 formed on the shaft II so as to effect a rotation of the holder withthe shaft, while permitting the holder to move axially of the shaft, asthe sealing ring l4 wears.

Leakage along the surface of the shaft is prevented by means of aresilient packing element If! that is preferably composed of any of thewellknown synthetic rubbers, suchas Duprene, or Neoprene. The element l9comprises a sleeve portion 20 that frictionally grips the surface of theshaft H with sufficient firmness to cause the sleeve 20 to rotate withthe shaft H and it also includes an'annular flange portion 2| thatsealably bears against one side of the holder IS. The sleeve 20 isstrengthened transversely of the shaft by a retaining ring 22 thatclosely encircles the sleeve and assists in maintaining the snugrelation of the sleeve to the shaft.

A pressure ring 23 encircles the retaining ring 22 and is held againstthe flange portion 2| by means of a helical spring that encircles theshaft II, the opposite end of the spring abutting against a ring 25 thatis held against axial movement by means of a collar 26 that is securedto the shaft in any approved manner. This spring accordingly providesthe required sealing pressure between the face of the boss [3 and thesealing ring l4, and also between the coacting faces of the flange 2|and holder ring l6. As before I3, the same result can be obtained bybushing 66 stated, leakage along the shaft is prevented by reason of thesealing contact of the sleeve 20 with the surface of the shaft. Thecollar 26 is intended to exemplify any type of abutment on the shaft.

When assembled on the shaft, the resilient packing element 19 is placedin the position approximately as shown in Fig. 1 and remains in thisposition throughout the life of the seal. As

the sealing ring it wears. the spring 24, acting through the flange 2 I,gradually moves the holder ring it toward the left until the sealingring I 4 has been completely worn. This axial movement of the holder IIis permitted by the flexibility inherent in the flange 2|.

It will be noted in particular that each of the sealing members of myimproved seal, namely, the sealing ring it and the resilient packingelement I 9, are separately driven from the shaft ii. In other words,this construction constitutes an improvement over seals of a similarcharacter wherein it is necessary to establish suflieient frictionalcontact between the flange 2i and the holder IS in order to insure thatthe latter will rotate with the shaft. Such a construction, however,places an undue burden on the packing element l9. This objection hasbeen entirely eliminated in my improved construction so that the elementI 9 is only called upon to fulflll its primary function, i. e., sealing.Moreover, with such a relation of the parts, it is possible tomaterially increase the useful life of the seal.

When seals of this-character are used-under conditions of hightemperature, such as, for example, in the circulating pump of a hotwater heating system, it has been ascertained that the materialcomposing the packing element I9 is prone to swell. In prior artconstructions, it has been the practice to encase the periphery of theelement It with a sleeve of some character, so that a material restraintis placed upon the swelling tendency of the element. In some instances,this restraint has been suflicient to cause a binding of the parts theseal with consequent damriphery of the flange ii is completely exposed,so that the paeldng element can freely expand in radial directions andthus accommodate itself to conditions of high temperature withoutcausing any damage to the seal.

I claim:

1. A seal for a wall and a, shaft extending therethrough having anon-circular, coaxial portion integrally formed thereon comprising arigid holder having an annular seal receiving socket and an axialopening for fitting the shaft portion to provide a direct drivingengagement therewith, the holder being axially shiftable on the portion,a sealing annulus mounted in the socket, resilient sealing means havinga portion frictionally engaging the shaft to provide a driving grip andsealing contact therewith and another portion for sealably contactingthe holder, and means for maintaining the sealing contact of the holderand last named portion.

2. A seal for a wall and a shaft extending therethrough having anon-circular, coaxial portion integrally formed thereon comprising arigid holder having an annular seal receiving socket and an axialopening therethrough for fltting the shaft portion to provide a drivingengagement therewith, the holder being axially shiftable on the portion,a sealing annulus mounted in the socket, resilient sealing meansfrictionally gripping the shaft for driving and sealing engagementtherewith and having an annular, flexible flange for contacting theholder, and means for maintaining sealing contact of the' holder andflange, the periphery of the flange being exposed and unconfined topermit radial swelling when exposed to high temperatures. I C. KEERAN.

